Spray a large skillet w/non stick cooking spray and heat to medium heat. I use a large electric skillet.
Mix ground chuck, onion, rice, egg, salt & pepper in a large bowl. Form walnut size meatballs and brown on all sides in skillet.
When completely brown, mix together cream of mushroom soup and onion soup mix. Pour over top of meatballs evenly, cover, reduce heat and simmer for 30 minutes, stirring occasionally and enjoy. We eat ours with either mashed potatoes or rice, a vegetable and rolls.
Note: If you don't have a large skillet, you can brown the meatballs and put them in a 9x13 greased baking dish and cover with the soup mixture. Bake for 30 minutes in a 350 degree oven.